Cylindrical rotor for use in a rasping machine

ABSTRACT

A cylindrical rotor for use in a rasping machine comprising a large number of blade-shaped rasping member extending parallel to the rotor axis and projecting in a radial direction out of the cylindrical surface, each member being secured by means of a tapered locking rod in a corresponding, tapered recess in the rotor, said recess having an axial clamping face in a direction away from the rotor axis, wherein at least part of the face of each locking rod on the side of the shaft and at least part of the corresponding bottom face of each recess are approximately at right angles to the supporting face and enclose an elongated, ondulated leaf spring, for allowing the movement of the locking rod in only one direction.

[ CYLINDRlCAL ROTOR FOR USE IN A RASPING MACHINE [75] Inventor: Johannes Jacobus Holthuis,

Veendam, Netherlands [73] Assignee: Nederlandeselndustrie voor Baggerwerktuigen Nivoba N.V., Veendam, Netherlands 22 Filed: Apr. 10.1973 21 Appl. No.: 349,769

[30] Foreign Application Priority Data Apr. 14, 1972 Netherlands 7205104 [52] US. Cl 29/105 R, 144/230, 29/78 [51] Int. Cl. B26d 1/12 [58] Field of Search 29/105 R, 105 A, 78;

[56] References Cited UNITED STATES PATENTS 1,225,552 5/1917 Wuesthoff 144/230 X 3,017,912 1/1962 Sybertz et al. 29/105 X Primary E.\'aminerLeonidas Vlachos Attorney, Agent, or FirmSnyder., Brown and Ramik [57] ABSTRACT A cylindrical rotor for use in a rasping machine comprising a large number of blade-shaped rasping member extending parallel to the rotor axis and projecting in a radial direction out of the cylindrical surface, each member being secured by means of a tapered locking rod in a corresponding, tapered recess in the rotor, said recess having an axial clamping face in a direction away from the rotor axis, wherein at least part of the face of each locking rod on the side of the shaft and at least part of the corresponding bottom face of each recess are approximately at right angles to the supporting face and enclose an elongated, ondulated leaf spring, for allowing the movement of the locking rod in only one direction.

3 Claims, 4 Drawing Figures PATENTEDHAR "41915 3,868,751

FIGJ.

CYLINDRICAL ROTOR FOR USE IN A RASPING MACHINE The invention relates to a cylindrical rotor for use in a rasping machine comprising a large number of bladeshaped rasping or grating members extending parallel to the rotor axis and projecting in radial direction out of the cylindrical surface, each member being secured by means of a tapered locking rod in a correspondingly tapered recess in the rotor, said recess having an axial clamping face and a supporting face converging towards the clamping face in the direction away from the rotor axis.

Such rotors are known in various designs, but each of them is liable to be improved. The invention provides such a rotor in which the rasping members can be arranged and reliably clamped in a simple and rapid manner. For this purpose said rotor is characterized in that at least part of the face of each locking rod facing the axis and at least part of the corresponding bottom face of each recess are approximately at right angles to the supporting face and enclose an elongated undulated leaf spring.

In this way, when a pressure force is exerted on the face remote from the axis the locking rod moves parallel to the supporting face since the undulated leaf spring enclosed between the parallel faces allows a movement in only one direction. Consequently, between the axial clamping face of the recess and the cor responding axial clamping face of the locking pin an intermediate space is left which can receive a bladeshaped rasping member, which can be clamped tight in the desired position after the pressure force is removed. It is advisable to arrange at least part of the face of each locking rod remote from the axis also approximately at right angles to said supporting face so that the pressure force required for providing the intermediate space can be exerted in a most advantageous manner and can be minimized.

In order to avoid complete flattening of the spring under the action of the pressure force, which might bring about damage or permanent deformation, it is advisable that between each locking rod and the bottom of thevcorresponding recess an abutment is provided so that the rod engages the rotor before the undulated leaf spring is completely flattened.

The invention will be described more fully with reference to the drawing, in which FIG. 1 is a partial axial elevationof a rotor without locking rods and blade-shaped rasping members,

FIG. 2 is a partial, perspective sectional view in an enlarged scale of the rotor shown in FIG. 1 with a rasping member fastened in a recess in said rotor by means of a locking rod,

FIG. 3 is a sectional view corresponding with that of FIG. 2, wherein a locking rod being pushed inwardly and FIG. 4 is a partial sectional view taken on the line IVIV in FIG. 2.

The axial elevation of FIG. 1 shows part of a cylindrical rotor ll embodying the invention, which rotor is provided with an axial bore 2 having a key-way for arranging the rotor on a driven shaft. In the rotor a plurality 2 from the rotor axis. The bottom 6 of each recess facing the axis is partly formed by a face 6 at right angles to 'the supporting face 5.

Into each recess 3 a locking rod 7 and an undulated leaf spring 8 are inserted in an axial direction, said rod being shaped in accordance with the recess and the leaf spring being enclosed between the bottom face portion 6 and the corresponding boundary face 9 of the locking rod 7.

i In order to arrange a blade-shaped rasping member in a recess 3 a pressure force is exerted in the direction of the arrow 11 on the face 12 of the locking rod 7 remote from the rotor axes so that the latter slides along the supporting face 5 of the recess by its supporting face 13 against the action of the spring 8. As a result a gap is formed between the clamping face 4 of the recess and the clamping face 14 of the locking rod for receiving the blade-shaped rasping member 10. When the pressure force is eliminated, the locking rod slides in the opposite direction owing to the action of the spring and clamps tightly against the rasping member.

In order fully to ensure that the movement of the locking rod 7 proceeds in the manner described and in order to minimize the force to be exerted, part of the side of each locking rod remote from the rotor axis is formed by a face 12' extending approximately at right angles to the supporting face, although, as a matter of course this face may constitute the whole side.

In order to avoid complete flattening of the undulated leaf spring 8 the movement of the locking rod 7 in the direction of the arrow 11 is restricted i.e., in the embodiment shown by providing the side of the locking rod facing the rotor shaft with an abutting face 9', which, when bearing on the corresponding bottom part 6" of the recess, maintains a predetermined minimum distance between the faces 6 and. 9 between which the undulated leaf spring is enclosed. a

It will be obvious that clamping of the rasping members during the standstill of the rotor and during the fitting of the rasping members in the rotor, is obtained by the action of the undulated leaf springs, whereas during the rotation of the rotor clamping is obtained practically completely under the action of the centrifugal of closely adjacent, axial elongated recesses 3 are ar- 6 force exerted on the tapered locking rod. Therefore, the forces exerted by theondulated leaf springs need only be sufficient for fixing the blade-shaped rasping members in the desired position during the standstill of the rotor.

What is claimed is:

1. A cutter assembly for use comprising, in combination:

a cylindrical rotor body adapted to be rotated about its longitudinal axis and having a plurality of longitudinally extending grooves therein, each groove defining a radially extending side face, a supporting face spaced from said face and extending in radially outwardly converging relation toward said side face, and a bottom face having a seating face portion thereof disposed at right angles to said supporting face; I

a cutting blade in each recess engaging a correspond ing side face and projecting radially outwardly from its groove to perform a cutting action as said body is rotated about its longitudinal axis;

a locking rod associated with each cutting blade,

each locking rod having opposite side surfaces disin rasping machines posed at that convergent angle defined between the side and supporting faces of each groove and each locking rod being dimensioned to fit within its groove with one side surface in face-to face contact with said cutting blade and the other side surface in face-to-face contact with said supporting surface, each said locking rod also having a bottom surface having a portion disposed in spaced, parallel relation to said seating face portion when its opposite side surfaces are engaged with said cutter blade and said supporting surface so that each locking rod is radially inwardly slidable along its supporting face to retreat from and disengage its cutting blade to permit movement of the cutting blade within the groove and a flat, undulated spring seated within each groove between said seating face portion and said portion of the bottom surface of the locking rod parallel thereto normally urging each said locking rod in locking engagement with its cutting blade.

2. A cutter assembly as defined in claim 1 wherein each locking rod includes an outer surface portion disposed at right angles to said other side surface thereof.

3. A cutter assembly as defined in claim 2 wherein the bottom face of each groove includes an abutment face portion and the bottom surface of each locking rod includes a portion engagable with said abutment face portion to limit inward sliding of the locking rod such that a space is always maintained between said seating face portion'of the groove and the bottom surface portion of the locking rod which is parallel thereto. 

1. A cutter assembly for use in rasping machines comprising, in combination: a cylindrical rotor body adapted to be rotated about its longitudinal axis and having a plurality of longitudinally extending grooves therein, each groove defining a radially extending side face, a supporting face spaced from said face and extending in radially outwardly converging relation toward said side face, and a bottom face having a seating face portion thereof disposed at right angles to said supporting face; a cutting blade in each recess engaging a corresponding side face and projecting radially outwardly from its groove to perform a cutting action as said body is rotated about its longitudinal axis; a locking rod associated with each cutting blade, each locking rod having opposite side surfaces disposed at that convergent angle defined between the side and supporting faces of each groove and each locking rod being dimensioned to fit within its groove with one side surface in face-to-face contact with said cutting blaDe and the other side surface in face-to-face contact with said supporting surface, each said locking rod also having a bottom surface having a portion disposed in spaced, parallel relation to said seating face portion when its opposite side surfaces are engaged with said cutter blade and said supporting surface so that each locking rod is radially inwardly slidable along its supporting face to retreat from and disengage its cutting blade to permit movement of the cutting blade within the gorrve; and a flat, undulated spring seated within each groove between said seating face portion and said portion of the bottom surface of the locking rod parallel thereto normally urging each said locking rod in locking engagement with its cutting blade.
 2. A cutter assembly as defined in claim 1 wherein each locking rod includes an outer surface portion disposed at right angles to said other side surface thereof.
 3. A cutter assembly as defined in claim 2 wherein the bottom face of each groove includes an abutment face portion and the bottom surface of each locking rod includes a portion engagable with said abutment face portion to limit inward sliding of the locking rod such that a space is always maintained between said seating face portion of the groove and the bottom surface portion of the locking rod which is parallel thereto. 